Desktop computer programs such as flight simulators, word-processors, and spreadsheets quickly respond to user input. Providing this kind of inter-activity over the Internet, however, has posed something of a challenge. This challenge stems, in part, from the simple communication model that describes most Internet traffic: clients (e.g., web-browsers) request pre-written web pages from servers, and the servers send the requested pages back for display.
Programmers have developed a number of different techniques to make web pages more inter-active. For example, some web pages include, or refer to, programs known as “applets.” When a browser receives a web-page featuring an applet, the browser executes the applet instructions, for example, to receive user input, change a browser GUI (Graphical User Interface) display, and communicate with the server providing the web-page. Some applets, however, include a large number of instructions and can require a significant amount of time to travel over the Internet to a user's browser.
Another technique for making web pages more responsive to users involves dynamic generation of web pages by servers. For example, PHP (Personal Home Page), ASP (Active Server Page), and CGI (Common Gateway Interface) scripts can dynamically produce a web page based on script instructions and variables. Script processing, however, adds yet another task to web-servers faced with handling large bursts of browser requests for information.